Microelectromechanical Systems (MEMS) sensors are widely used in applications such as automotive, inertial guidance systems, household appliances, protection systems for a variety of devices, and many other industrial, scientific, and engineering systems. Such MEMS sensors are used to sense a physical condition such as acceleration, pressure, angular rotation, or temperature, and to provide an electrical signal representative of the sensed physical condition.
Capacitive MEMS accelerometers typically include a movable mass that is suspended from a substrate. The movable mass moves, i.e., rotates or translates depending upon the design and sensing direction, in response to an acceleration force. Motion of the movable mass results in a change in electrical capacitance, with respect to the acceleration force, to vary the output of an energized circuit. MEMS accelerometers are often subject to high acceleration forces, referred to herein as shock events, in off-axis directions. Unfortunately, the spring suspension designs used to suspend a movable mass may not be robust to such shock events leading to device failure.